Grinding shoe and die.



No. 874,414. PATENTED DEC. 24, 1907. W. MIDDLETON & H.,N. G. COBBE;

GRINDING SHOE AND DIE APPLICATION FILED'AUG.28,1905.

2 SHEETS-SHEET 1.

Tu: NORRIS FETERS C0,, WASHINGTON, n. c,

No. 874,414. v 'PATENTED DEC. 24, 1907.

W. MIDDLETON & H. N. G. OOBBB.

GRINDING SHOE AND DIE.

APPLICATION FILED AUG. 28, 1905.

2 SHEETS-SHEET 2.

1H: NORRIS PETERS ca., wnsmna1ou, D. c

UNITED STATES PATENT @FFIOE. 1

WILLIAM MIDDLETON AND HERVIG NUGENTGRAHAME GOBBE, OF KALGOORLIE, WESTERN AUSTRALIA, AUSTRALIA.

GRINDING SHOE AND DIE.

Specification of Letters Patent.

Patented Dec. 24;, 1907.

Application filed August 28 1905. Serial No. 276,130.

To all whom it may concern:

Be it known that we, IVILLIAM MIDDLE- TON and HERvIo NUGENT GRAHAME OoBBE, both citizens of the Commonwealth of Australia, and residing at Kalgoorlie, Western Australia, Australia, have invented certain new and useful Improvements in Grinding Shoes and Dies; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters or figures of reference marked thereon, which form a part of this specification.

In the existing constructions of the grinding surfaces of crushing appliances it is found that such surfaces at their circumferential edges form ridges, walls or ledges with corresponding depressions on the companion face or vice-versa, that is, that such faces at or near their circumferential edges becom either over or under shot during use and wear so causing the one surface to cup or nest into its companion and thus impeding the discharge and otherwise reducing the finished output of the machine. Such ridging or non-uniform wear may arise among other causes from the initial inequalities of the faces or from inaccurate or untrue setting or fitting together and such fault becomes intensified during the use and wear of the parts concerned.

The invention is applicable to all forms of companion grinding surfaces either those of the abrasive type as pans or of a rolling type as revolving mills and in which are used shoes, dies, false bottoms, runners or rings, or other such like frictional agents either fixed or movable employed for crushing purposes.

This invention has been designed to arrest and overcome such faulty disposition of these wearing surfaces by making the inner or outer peripheral rims or faces of the grinding surface either in whole or part to be of a ridge releasing construction by being made of a broken-up or cut-out formation as, say, by means of ribs serrations, grooves, channels, projections and analagous or equivalent overhung or undercut forms.

The invention will now be explained in conjunction with the attached drawings in which are illustrated alternative constructions'of the peripheral ribs.

In such drawings-Figure 1 shows the companion grinding faces having the ribs of a serrated section. Fig. 2 shows the same faces placed in a reverse manner. Fig. 3 shows the ribs of a square section, and Fig. 4 shows the ribs of a similar section but hav ing curved troughs and in Fig. 5 the ribs are shown of a sense or non-continuous form. Fig. 6 1s a section of a Well known standard amalgamating pan equipped with dies and shoes made in accordance with my invention.

In these figures the upper and lower grinding surfaces are denoted by the letters a and b respectively. These surfaces are formed on their rims with the peripheral ribs or serrations as 0 so thereby having the repetitional circumferential faces as (Z and. which come into use in due rotation as in course of wear.

In Figs. 1 and 2 we have shown the circumferential ribs on the shoes at and on the dies 1) provided with oppositely beveled faces 0 so that during use they will wear symmetrically with respect to one another and the material being ground will not be held in any pocket at the edge of the cooperating grinding faces.

Referring to Fig. 5 in which such peripheral formations or ribs are shown as subdivided. into any number of divisions as e by having open spaces or cut-outs as f and so made non-continuous with the object that the ridge or ridges when formed may the more easily break away or fall off than if such peripheral rib were. made in one horizontal piece.

In Fig. 6 I have shown a section of a well known form of amalgamating pan in which the pan 7 is provided with the usual rotating muller plates 8 to which are secured the rotary shoesa made in accordance with the present invention and the fixed dies 1) alsomade in accordance with the presentinvention and secured to the bottom of the pan 7. The other operative parts are of a well known construction and require no further description.

Such release constructions therefore provide a series or multiple number of new and repetitional faces at-or near the circumferential edges with the result that such ledge or ridge as soon as it has arrived at or worn to its depth (which depth is governed by the depth of the serration or projection) the said ledge or ridge will drop or break off so that the new and non-ridged grinding face at the circumferential edge will come into operation. These formations as c by which either the inner or outer peripheries of the grinding surfaces as a and b are broken up may be either of a serrated, projectional or grooved shape and we do not limit ourselves to any precise form as such may be altered or amplified to suit the different requirements or matters being treated or crushed.

What we do claim as our invention and de sire to secure by Letters Patent is 1. In a grinding pan, a grinding shoe and a die having their sides provided with serrations to prevent the grinding faces from becoming over or under shot.

2. In a grinding pan, a grinding shoe and a die having their sides provided with substantially parallel serrations.

3. In a grinding pan, the combination with a shoe having lateral serrations beveled in one direction; of a die having lateral serrations beveled in an opposite direction.

4. In a grinding pan, a grinding die having peripheral serrations substantially parallel with the grinding face and beveled in one direction, in combination with a grinding shoe having peripheral serrations also substantially parallel with its grinding face and beveled oppositely to those on the die and means to rotate the shoe relatively to the die.

In testimony that we claim the foregoing as our invention, we have signed our names in presence of two subscribing witnesses.

WILLIAM MIDDLETON. HERVTC NUGEN'J GRAHAME COBBE.

Vitnesses NORBERT KEENAN, T. C. CURwooD. 

